1. Field of the Invention
The present invention relates to a rollover protection system (ROPS) for a working vehicle having a rollover protection bar assembly extending over a vehicle body.
2. Description of the Related Art
This type of rollover protection system, as disclosed in U.S. Pat. No. 4,877,265 or U.K. Patent Publication GB 2 174 259A, has a rollover protection bar assembly extending over a vehicle body to be adjustable in height. During an ordinary operation, for example, the rollover protection bar assembly is raised to protect the driver in case the working vehicle should overturn. During an operation in a vertically limited space, or when putting the vehicle into a barn (in the case of an agricultural working vehicle), the rollover protection bar assembly is lowered to facilitate the operation or storage.
The conventional rollover protection system noted above includes two or more protective bars simply joined together by means of bolts or pins. For changing height of the rollover protection bar assembly, the bars are disconnected and connected again by removing and inserting the bolts or pins. This is not only a troublesome operation, but components of the rollover protection bar assembly could be lost such as by dropping the bolts or pins. Thus, there is room for improvement in handling convenience.